Eurostar, UK, France and Belgium

The cross-channel operator has shouted louder than most other rail companies about its green credentials, but with good reason. In 2007 it committed to reduce CO2 emissions by 25% per traveller by 2012, but by the end of 2008 it had already achieved a 31% reduction – so it has now revised its 2012 pledge to a 35% reduction. It has also improved the provenance of the on-board food it serves.• 0843 218 6186, eurostar.co.uk

Green Tomato Cars, London

This ambitious private-hire car firm launched in March 2006 with just four vehicles, and now has 110 Toyota Prius cars carrying more than 40,000 passengers a month across London. The company says the use of its low-emission cars "has resulted in the avoidance of around 1,200 tonnes of CO2 that would have been emitted had our passengers travelled in black taxis." A spokesperson also confirmed that all its cars affected by the recent Toyota recall "have since been upgraded and are functionally normally".• 020-8568 0022, greentomatocars.com

Arriva, Europe

Bus and train operator Arriva is one of the largest transport organisations in Europe. It has extensively trialled the use of biofuel blends in both trains and buses, and also trialled an emissions control initiative on its buses known as EcoManager, training drivers to be more fuel efficient and improving vehicle performance, which the company says saved more than 100,000 litres of fuel and over 260 tonnes of CO2. The system has been fitted in 3,000 buses in the UK, and equivalent technology is to be introduced into Arriva's fleet of 2,300 buses in Sweden and Denmark.• +44 191 520 4000, arriva.co.uk

Brittany Ferries, UK, France and Spain

The cross-channel ferry operator, which also operates from the UK to northern Spain, has carried out a number of fuel-efficiency programmes, including rescheduling most crossings, which it says saved around 2,000 tonnes of fuel during 2008. From July all its cruise-ferries will begin using fuel with a reduced sulphur content. On its ferries across the Bay of Biscay (one of the best places in Europe to spot whales and dolphins), it hosts researchers from marine research organisation Orca, who give presentations and relay sightings en-route.• 0871 244 0744, brittanyferries.co.uk